The present disclosure relates generally to vascular access devices and methods, including catheter assemblies and devices used with catheter assemblies. Generally, vascular access devices are used for communicating fluid with the vascular system of patients. For example, catheters are used for infusing fluid, such as saline solution, various medicaments, and/or total parenteral nutrition, into a patient, withdrawing blood from a patient, and/or monitoring various parameters of the patient's vascular system.
A variety of clinical circumstances, including massive trauma, major surgical procedures, massive burns, and certain disease states, such as pancreatitis and diabetic ketoacidosis, can produce profound circulatory volume depletion. This depletion can be caused either from actual blood loss or from internal fluid imbalance. In these clinical settings, it is frequently necessary to infuse blood and/or other fluid rapidly into a patient to avert serious consequences.
Additionally, the ability to inject large quantities of fluid in a rapid manner may be desirable for certain other medical and diagnostic procedures. For example, a power injection of a contrast agent may be desirable for conducting a scanning procedure, such as a computed tomography (CT) scan. For this procedure, an injection rate of about 1 to 10 ml/second is needed to ensure sufficient distribution of the contrast agent during the scanning procedure. A power injection of a highly viscous liquid may also be desirable. For example, a medical or diagnostic procedure may require a rapid injection of a fluid with a high viscosity at an injection rate of about 1 to 10 ml/second. Power injections at this injection rate produce significant back pressure within the infusion system that may result in a failure of the infusion system components.
In the past, power injection of highly viscous fluids, as well as rapid infusions to replace large amounts of fluids has been a major problem to the medical and surgical teams attending patients with these acute needs. A common method of rapid infusion involves the simultaneous use of a plurality of infusion sites. Frequently, a plurality of medical personnel is required to establish and oversee the various infusion sites and to ensure the flow of fluids from their respective fluid sources. This method may be limited by the number of peripheral or central sites that can be physically accessed in a given patient, the number of people attending the fluids being infused, as well as the efficiency of infusing the fluids during a dire, hypovolemic event. It is not uncommon for four to five anesthesiologists or technicians to stand in attendance during transplant operations lasting more than twenty-four hours attempting to infuse massive quantities of blood through five or six venous catheters.
Patients who have undergone massive trauma or surgery such as liver transplantations or other elective procedures may require voluminous quantities of fluids to maintain a viable circulatory state. Although it is not uncommon for an anesthesiologist or surgeon in a major trauma center to encounter massive exsanguinations of ten liters or more, it is unusual to successfully resuscitate a patient with such massive blood volume loss using traditional methods.
Traditionally, rapid infusion therapy entails the use of a venous catheter attached to a peristaltic pump and a fluid source. A patient is infused as a tip portion of the catheter is inserted into the vasculature of a patient and the pump forces a fluid through the catheter and into the patient's vein. Intravenous infusion rates may be defined as either routine, generally up to 999 cubic centimeters per hour (cc/hr), or rapid, generally between about 999 cc/hr and 90,000 cc/hr (1.5 liters per minute) or higher. Current rapid infusion therapies utilize a catheter and catheter tip with geometries identical to those used with traditional, routine infusion rates. These geometries include a tapering catheter tip such that the velocity of a fluid is accelerated as the fluid moves through the catheter tip and exits into a patient's vasculature. This acceleration of the infused fluid is undesirable for several reasons.
For example, the tapered catheter results in a greater backpressure and/or recoil force for the remainder of the catheter assembly. This effect is undesirable due to the limitations of the pumping capacity of the infusion pump as well as the limited structural integrity of the components and subcomponents of the infusion system. For example, if the backpressure becomes too great, the pump's efficiency may decrease and certain seals or connections within the infusion system may fail. Additionally, a greater recoil force may cause the catheter tip to shift within the patient's vein thereby displacing the catheter and/or damaging the patient's vein and/or injection site.
Additionally, the accelerated infusant may infiltrate the patient's vein wall thereby damaging the patients vein and leading to extravasation. Not only is this uncomfortable and/or painful to the patient, but infiltration may also decrease the infusion rate and prevent the patient from receiving the needed infusant. Accordingly, the problem of backpressures and/or recoil forces during rapid infusion procedures remains to be solved. The present disclosure presents systems and methods to significantly limit and/or prevent such undesirable recoil forces during rapid infusion procedures.